Expandable Shell of a Suitcase

ABSTRACT

An expandable shell of a suitcase includes first and second surrounding shell bodies mated with and stackable on each other and cooperatively defining an expandable accommodation chamber for increasing the volume of the suitcase. A control unit includes a pulling cord secured to the first surrounding shell body and reeled on a reel member that is mounted to the second surrounding shell body, and a pawl and ratchet teeth disposed to control the rotation of the reel member so as to adjust a distance between the first and second surrounding shell bodies and the volume of the expandable accommodation chamber.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Chinese Utility Model ApplicationNo. 200920174026.2, filed on Aug. 26, 2009, the disclosure of which isherein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a suitcase, more particularly to an expandableshell of a suitcase.

2. Description of the Related Art

A conventional suitcase generally includes a flexible expandable sectionwhich is displaceable between an expanded position for increasing thevolume of the suitcase, and a retracted position where the flexibleexpandable section is folded and retained by a zipper. Thus, the volumeof the suitcase can be varied by virtue of the flexible expandablesection. However, no rigid structure is provided to support the flexibleexpandable section in the expanded position so that the structuralstrength of the suitcase is weak in use. Moreover, no adjusting means isprovided for adjusting the volume of the flexible expandable section soas to meet the user's requirement.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an expandable shell ofa suitcase which has sufficient structural strength and the volume ofwhich is adjustable.

According to this invention, the expandable shell includes first andsecond surrounding shell bodies surrounding a longitudinal axis andconfigured to mate with and to be stackable on each other so as tocooperatively define an expandable accommodation chamber for increasingthe volume of the suitcase. A pulling cord has an anchoring end securedto the first surrounding shell body, and a cord body which extends fromthe anchoring end to terminate at a connected end. A reel member isrotatably mounted to the second surrounding shell body, and isconfigured to permit the connected end to be secured thereon such that,by means of rotation of the reel member, the cord body is reeled in orout to shorten or lengthen a distance between the first and secondsurrounding shell bodies. The reel member has a flange which surroundsthe reel axis and which is formed with a plurality of ratchet teeth thatare angularly displaced from one another. A reel spring is disposed tobias the reel member to perform a reel-in movement. A pawl is movablerelative to the reel member between a blocking position, where aretaining end of the pawl is engaged with one of the ratchet teeth so asto guard against a reeling-out movement of the reel member, and afree-rotating position, where the retaining end is disengaged from thereel member to permit the reel member to reel out the cord body. A pawlspring is disposed to bias the pawl to the blocking position. Anextension spring is disposed to bias the second surrounding shell bodyaway from the first surrounding shell body so as to enlarge theexpandable accommodation chamber, and has a biasing force larger thanthat of the reel spring such that, once the pawl is moved to thefree-rotating position, the second surrounding shell body is pushed awayfrom the first surrounding shell body by the biasing force of theextension spring, while the cord body is permitted to be reeled out fromthe reel member against the biasing force of the reel spring.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will becomeapparent in the following detailed description of the preferredembodiment of the invention, with reference to the accompanyingdrawings, in which:

FIG. 1 is a perspective view of the preferred embodiment of anexpandable shell according to this invention in an expanded position;

FIG. 2 is a fragmentary sectional view of a guiding unit of thepreferred embodiment taken along line II-II of FIG. 1;

FIG. 3 is an exploded perspective view of a control unit of thepreferred embodiment;

FIG. 4 is a fragmentary plan view of the control unit in a blockingstate;

FIG. 5 is a fragmentary plan view of the control unit in an operatedstate; and

FIG. 6 is a perspective view of the preferred embodiment when folded.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, the preferred embodiment of an expandable shell ofa suitcase according to the present invention is shown to comprise afirst surrounding shell body 10, a second surrounding shell body 20, aplurality of guiding units 30, and two control units 40.

The first surrounding shell body 10 is of a rectangular shape, andsurrounds a longitudinal axis in a longitudinal direction. The firstsurrounding shell body 10 includes two first long walls 11 and two firstshort walls 12 interconnecting the first long walls 11.

The second surrounding shell body 20 is substantially the same as thefirst surrounding shell body 10 and includes two second long walls 21and two second short walls 22 interconnecting the second long walls 21.The second surrounding shell body 20 surrounds the longitudinal axis andis disposed to mate with and to be stackable on the first surroundingshell body 10 so as to cooperate with the first surrounding shell body10 to define an expandable accommodation chamber (A) for increasing thevolume of the suitcase.

With reference to FIG. 2, each of the guiding units includes first andsecond mounting seats 31,32 respectively secured on the first and secondlong walls 11,21 and disposed opposite to each other in the longitudinaldirection, first and second tubular members 33,34 which are respectivelysecured on the first and second mounting seats 31,32, which extend inthe longitudinal direction toward each other, and which aretelescopically fitted to each other to forma tubular unit that ismovable between retracted and extended positions, and an extensionspring 35 which is disposed in the tubular unit to bias the secondsurrounding shell body 20 away from the first surrounding shell body 10in the longitudinal direction and to urge the tubular unit toward theextended position so as to enlarge the expandable accommodation chamber(A).

With reference to FIGS. 3 and 4, each of the control units 40 includes amount 41 secured to the second surrounding shell body 20, a positioningmount 42 secured to the first surrounding shell body 10 and disposedopposite to the mount 41 in the longitudinal direction, a reel member 43pivotably mounted on the mount 41, a reel spring 44 mounted on the mount41 and biasing the reel member 43 to perform a reel-in movement (R), apawl 44 pivotably mounted on the mount 41 to engage the reel member 43,a pawl spring 46, a push button 47, a button spring 48, and a pullingcord 49.

The mount 41 defines an accommodation space 411 and a slot 414, and hasan axle 412 disposed in the space 411 and extending along a reel axisthat is transverse to the longitudinal direction, and a guide rail 413extending in the longitudinal direction.

The positioning mount 42 has a retaining cavity 421 and a guiding slot422 in spatial communication with the retaining cavity 421.

The reel member 43 is received in the accommodation space 411, isrotatably mounted on the axle 412, and has a cord reeling portion 431,and a flange 432 which surrounds the reel axis and which is formed witha plurality of ratchet teeth 433 that are angularly displaced from oneanother.

The reel spring 44 is a coil spring having two ends respectively securedon the axle 412 and the reel member 43. The extension spring 35 has abiasing force larger than that of the reel spring 44.

The pawl 45 has a retaining end 451 and a force-transmitting end 452,and is pivotable between a blocking position, where the retaining end451 is engaged with one of the ratchet teeth 433 so as to guard againsta reeling-out movement (R′) of the reel member 43, and a free-rotatingposition, where the retaining end 451 is disengaged from the reel member43 to permit the reeling-out movement (R′) of the reel member 43. Thepawl spring 46 is a torsion spring disposed to bias the pawl 45 to theblocking position.

The push button 47 is mounted in the guide rail 413 and is manuallyoperable to perform a stroke movement in the longitudinal direction soas to move the pawl 45 to the free-rotating position.

The button spring 48 is disposed between the mount 41 and the pushbutton 47 to bias the push button 47 against the stroke movement.

The pulling cord 49 has an anchoring end 491 which is led into theretaining cavity 421 through the guiding slot 422. A retained block 494is connected to the anchoring end 491 and is received in the retainingcavity 421 so as to secure the anchoring end 491 in the retaining cavity421. The pulling cord 49 further has a cord body 493 which extends fromthe anchoring end 491 in the longitudinal direction to terminate at aconnected end 492. The connected end 492 is secured on the reel member43 such that, by means of rotation of the reel member 43, the cord body493 is reeled in or out to shorten or lengthen a distance between thefirst and second surrounding shell bodies 10,20.

Reference is made to FIGS. 5 and 6 which illustrate the expandable shellof the suitcase in a non-expanded state, i.e., having a smallest volume.In this state, the second surrounding shell body 20 is stacked on thefirst surrounding shell body 10, the extension spring 35 is in acompressed state, and a major portion of the cord body 493 is reeled inon the cord reeling portion 431.

Referring again to FIGS. 2 and 4, when it is desired to extend theexpandable shell to increase the volume of the suitcase, a pressingforce is applied to the pushbutton 47 to actuate the force-transmittingend 452 of the pawl 45 so as to move the pawl 45 to the free-rotatingposition. The second surrounding shell body 20 can be pushed away fromthe first surrounding shell body 10 by the biasing force of theextension spring 35, while the cord body 493 is permitted to be reeledout from the reel member 43 against the biasing force of the reel spring44. Once the pressing force is released from the push button 47 toresult in engagement between the retaining end 451 of the pawl 45 andone of the ratchet teeth 433 of the reel member 43, the reel-outmovement (R′) of the reel member 43 is prevented so as to position thefirst and second surrounding shell bodies 10,20 in place. Thus, thevolume of the expandable shell can be adjusted readily.

When it is desired to reduce the volume of the suitcase, the user canpress the first and second surrounding shell bodies 10,20 toward eachother against the biasing force of the extension spring 35. By virtue ofthe biasing force of the reel spring 44, the reel member 43 can performa reel-in movement (R) to reel in the pulling cord 49, and the ratchetteeth 433 can alternately slap against the retaining end 451 of the pawl45 to provide audible and tactile feedback to the user until the tubularunit is placed in the retracted position as shown in FIGS. 5 and 6. Ifthe user inadvertently releases the first and second surrounding shellbodies 10,20, due to the engagement between the pawl 45 and the reelmember 43, relative movement between the first and second surroundingshell bodies 10,20 can be restricted.

As illustrated, the expandable shell according to this invention isextendable and retractable to adjust the volume of the suitcase. Inaddition, with the provision of the first and second surrounding shellbodies 10,20 and the guiding units 30, the structural strength of thesuitcase can be enhanced.

While the present invention has been described in connection with whatis considered the most practical and preferred embodiment, it isunderstood that this invention is not limited to the disclosedembodiment but is intended to cover various arrangements included withinthe spirit and scope of the broadest interpretations and equivalentarrangements.

1. An expandable shell of a suitcase, comprising: a first surroundingshell body surrounding a longitudinal axis in a longitudinal direction;a second surrounding shell body surrounding the longitudinal axis andconfigured to mate with and to be stackable on said first surroundingshell body so as to cooperate with said first surrounding shell body todefine an expandable accommodation chamber for increasing volume of thesuitcase; a control unit including a pulling cord having an anchoringend which is secured to said first surrounding shell body, a cord bodywhich extends from said anchoring end in the longitudinal direction toterminate at a connected end, a reel member which is rotatably mountedto said second surrounding shell body about a reel axis that istransverse to the longitudinal direction, and which is configured topermit said connected end to be secured thereon such that, by means ofrotation of said reel member, said cord body is reeled in or out toshorten or lengthen a distance between said first and second surroundingshell bodies, said reel member having a flange which surrounds the reelaxis and which is formed with a plurality of ratchet teeth that areangularly displaced from one another, a reel spring disposed to biassaid reel member to perform a reel-in movement, a pawl having aretaining end and movable relative to said reel member between ablocking position, where said retaining end is engaged with one of saidratchet teeth so as to guard against a reeling-out movement of said reelmember, and a free-rotating position, where said retaining end isdisengaged from said reel member to permit said reel member to reel outsaid cord body, and a pawl spring disposed to bias said pawl to theblocking position; and an extension spring disposed to bias said secondsurrounding shell body away from said first surrounding shell body inthe longitudinal direction so as to enlarge said expandableaccommodation chamber, and having a biasing force larger than that ofsaid reel spring such that, once said pawl is moved to the free-rotatingposition, said second surrounding shell body is pushed away from saidfirst surrounding shell body by the biasing force of said extensionspring, while said cord body is permitted to be reeled out from saidreel member against the biasing force of said reel spring.
 2. Theexpandable shell according to claim 1, wherein said control unit furtherincludes a push button configured to be manually operable to perform astroke movement in the longitudinal direction relative to said secondsurrounding shell body so as to move said pawl to the free-rotatingposition.
 3. The expandable shell according to claim 2, wherein saidcontrol unit further includes a mount which is secured to said secondsurrounding shell body and which has an axle extending along the reelaxis for mounting said reel member thereon, and a guide rail whichextends in the longitudinal direction for guiding said push button toperform the stroke movement, and a button spring which is disposedbetween said mount and said push button to bias said push button againstthe stroke movement.
 4. The expandable shell according to claim 3,wherein said control unit further includes a positioning mount which issecured to said first surrounding shell body and which has a retainingcavity and a guiding slot that is in spatial communication with saidretaining cavity to permit said anchoring end to be led into saidretaining cavity, and a retained block which is retained in saidretaining cavity, and which is configured to secure said anchoring endin said retaining cavity.
 5. The expandable shell according to claim 1,further comprising: first and second tubular members which are disposedto extend respectively from said first and second surrounding shellbodies in the longitudinal direction toward each other and which aretelescopically fitted to each other to form a tubular unit which ismovable between retracted and extended positions; said extension springbeing disposed in said tubular unit so as to bias said tubular unittoward the extended position.